In a nutshell

This study aimed to see if a closed-loop insulin delivery system (an automatic insulin delivery system) could control blood sugar levels better than the traditional patient-controlled insulin pump in patients with type 1 diabetes (T1D). The main finding was that the closed-loop insulin delivery system improved blood sugar controlin these patients.

Some background

Insulin therapy is currently the only treatment for T1D. Insulin can be self-injected by the patient or administered by an insulin pump. One of the insulin pumps available on the market is called a sensor-augmented pump (SAP). This pump continuously measures blood sugar levels. At the same time, it delivers a low dose of insulin. The sensor alerts the patient if their blood sugar has gone too high or too low and the patient can alter the insulin dose accordingly.

The newest insulin pump is called a closed-loop (CL) insulin delivery system. This pump works by continuously measuring blood sugar levels and automatically changing the insulin dose accordingly. It is important to determine which device is the most effective for glycemic (blood sugar) control in patients with T1D.

Methods & findings

This study included 86 patients with poorly controlled T1D. 46 patients were randomly assigned to receive their insulin via a CL delivery system. The other 40 received their insulin via an SAP. All patients underwent a run-in period of 4 weeks. The study lasted for another 12 weeks. The effectiveness of the devices was measured through the HbA1c (an average of blood sugar levels of the past 3 months).

After the 12 weeks of study, both groups saw improvements in HbA1c levels. There was a greater improvement in HbA1c levels n the CL group (by 0.9%) compared to the SAP group (by 0.5%). The patients in the CL group saw the greatest benefits for blood sugar control during the night.

No significant side-effects related to the treatments were reported.

The bottom line

The authors concluded that the closed-loop insulin delivery systems can improve blood sugar control in patients with poorly controlled type 1 diabetes.

The fine print

Only patients with HbA1c of 7.5-10% were included in the study. Therefore, there is no data on patients with severely uncontrolled T1D. The study period was rather short. Longer-term studies are needed to confirm results.

What’s next?

If you have any concerns about glycemic control, discuss a closed-loop insulin delivery system as a treatment option with your doctor.